The present invention relates to a wafer transport method, and particularly to a wafer transport method which is used in a semiconductor process equipment having a process chamber and a transport chamber.
A through process equipment for semiconductor devices has been known, for example in Unexamined Japanese Patent Publication No. HEI 4-63414, wherein a plurality of process chambers for cleaning, deposition, etching, exposure of latent image are disposed around a transport chamber for preventing the contamination of a wafer surface thereby improving the performance of a semiconductor device. A means of transporting a substrate between different atmospheres has been also described in Unexamined Japanese Patent Publication No. SHO 62-147726, wherein a substrate is transported by moving a holder mounting the substrate by way of a communicating corridor, a prior exhaust chamber, and the communicating corridor.
In the above-described prior art references, the through process equipment requires partitioning each process chamber from a transport chamber by means of a gate valve, and adjusting an atmospheric pressure in each process chamber and opening/closing the gate valve connected to the transport chamber for each wafer transport, thereby causing a disadvantage in lowering the throughput. The method of transporting a substrate while keeping the conditions of the process chambers with different atmospheres is disadvantageous in that an atmospheric gas flows in the prior exhaust chamber from each process chamber and a transport chamber by way of a gap formed between the communicating corridor and the holder, thereby contaminating a substrate mounted on the holder.